Keelung Nuannuan pothole
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Keelung Nuannuan pothole is potholes or kettle holes in the exposed bed of the Keelung River at Nuannuan District, Keelung City in Taiwan. These potholes are a circular indentation on the riverbed carved out into solid rock. It is formed by a kind of drilling action when pebbles are caught in eddy currents and whisked around within a small natural crack or hollow. As time passes, the drilling action enlarges the hollow to form a pothole. Potholes are commonly found below waterfalls or rapids where significant hydraulic action is found. [1]
These naturally occurring potholes are of great interest to geologists. They are quite uncommon. The best-known kettle holes in Taiwan are a mass of indents in the exposed bed of the Keelung River at the town of Nuannuan, near Keelung City. These well-known potholes lie right beside a busy road. Near Nuannuan, the Keelung River is narrow with faster flowing water and turbulence. The faster flowing water and turbulence results in the formation of these potholes. [2] Riverbed potholes take hundreds of years to form. It is an important geological feature. The formation phenomena provokes wide research interests in fluid dynamics, landscape, geology, climate, hydrological and rock studies. Its rarity also serves as an educational resource for everybody.
